Barnard's Star (GJ 699) is a nearby, high velocity (UVW =
-148,+0,+16 km/s), Thick Disk / Intermediate-age Pop II dM4
star. Although old (7-12 Gyr), Barnard's Star appears to be
magnetically active, having coronal X-ray emission as well
as moderately strong chromospheric UV emissions. Barnard's
star holds the speed record for having the largest proper
motion of any star yet known (10.4"/yr). At a distance of
only 1.82 pc (5.9 lt yrs), it is the nearest star to us
after the \alpha Cen system. Recent measures of Barnard's
Star results in a luminosity of L = 3.46 ± 0.17 \times
10-3 L\odot, R = 0.20 ± 0.008 R\odot, and
Teff = 3134 ± 102 K (Dawson & De Robertis 2004,
AJ, 127, 2909). Because of its proximity and age, we have
selected Barnard's Star for more intensive study, and to
serve as a proxy for the numerous old-population dM stars in
our Galaxy. These stars may be targets of future planet
search missions such as SIM, Kepler, and TPF/Darwin in the
next several years. For exobiology, dM stars make
interesting targets because the habitable zones (HZ) around
dM stars are close to the host star (HZ ~ 0.05-0.40
AU), making the hypothetical HZ planet more strongly
influenced by stellar flares, winds, and plasma ejection
events that are frequent in dM stars.

We are conducting intensive photoelectric UBVRI and
TiO (719nm) photometry of Barnard's Star using the
Four College Automatic Photoelectric Telescope in Arizona.
This photometry is being conducted to determine starspot
coverage and the rotation period. We have also determined
X-ray to UV irradiances that will characterize dM stars of
similar ages. These measures will be useful in the future if
large numbers of older dM stars are found to harbor planets.
We will discuss the results of this study, which is a
component of a larger program aimed at improving (and
testing) our understanding of magnetic-related phenomena in
dM stars. This research is supported by NASA and NSF/RUI
grants.